Many changes here and there. I lost track... :-(

Current work is on MLSE and SD Decoding etc. MLSE is currently not 100% working, the scalings are maybe off?!
This commit is contained in:
Silas Oettinghaus
2025-08-11 07:42:04 +02:00
parent 09d9e5011c
commit 5dbc48abc0
37 changed files with 1506 additions and 570 deletions

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@@ -1,6 +1,6 @@
function [output] = imdd_model(varargin)
simulation_mode = 0;
simulation_mode = 1;
%%% Change folder
curFolder = pwd;

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@@ -1,33 +1,24 @@
%%% Run parameters
% TX
M = 4;
fsym = 180e9;
fsym = 112e9;
apply_pulsef = 1;
fdac = 256e9;
fadc = 256e9;
random_key = 1;
db_precode = 0;
db_encode = 0;
random_key = 2;
rcalpha = 0.05;
kover = 16;
vbias_rel = 0.5;
u_pi = 2.9;
vbias = -vbias_rel*u_pi;
laser_wavelength = 1310;
laser_wavelength = 1290;
laser_linewidth = 0;
tx_bw_nyquist = 0.6;
rx_bw_nyquist = 0.6;
% Channel
link_length = 1;
% RX
rop = -8;
link_length = 10000;
vnle_order1 = 50;
vnle_order2 = 3;
@@ -49,55 +40,13 @@ mu_dc = 0.005;
mu_ffe = [mu_ffe1 mu_ffe3 mu_ffe3];
mu_dfe = 0.0004;
dfe_ = sum(dfe_order)>0;
doub_mode = db_mode.no_db;
Pform = Pulseformer("fsym",fsym,"fdac",4*fsym,"pulse","rc","pulselength",16,"alpha",rcalpha);
db_precode = 0;
db_encode = 0;
duob_mode = db_mode.no_db;
apply_pulsef = 1;
[Digi_sig,Symbols,Tx_bits] = PAMsource(...
"fsym",fsym,"M",M,"order",18,"useprbs",0,...
"fs_out",fdac,...
"applyclipping",0,"clipfactor",1.5,...
"applypulseform",apply_pulsef,"pulseformer",Pform,...
"randkey",random_key,...
"db_precode",db_precode,"db_encode",db_encode,...
"mrds_code",0,"mrds_blocklength",512,"duobinary_mode",duob_mode).process();
Digi_sig.spectrum("displayname",'Digi Spectrum','fignum',10,'normalizeTo0dB',1);
%%%%% AWG
% El_sig = M8199A("kover",kover).process(Digi_sig);
El_sig = AWG("fdac",fdac,"f_cutoff",fsym,"lpf_active",0,"kover",kover,"bit_resolution",12,"upsampling_method","samplehold","precomp_sinc_rolloff",1).process(Digi_sig);
% El_sig.spectrum("displayname",'Digi Spectrum','fignum',100,'normalizeTo0dB',0);
% El_sig = El_sig.setPower(0,"dBm");
%%%%% Low-pass el. components %%%%%%
f_nyquist = fsym/2;
tx_bwl = tx_bw_nyquist.*f_nyquist;
% tx_bwl = 80e9;
El_sig = Filter('filtdegree',4,"f_cutoff",tx_bwl,"fs",fdac*kover,"filterType",filtertypes.butterworth,"active",true).process(El_sig);
% El_sig.spectrum("displayname",'Digi Spectrum','fignum',100,'normalizeTo0dB',1);
%%%%% Electrical Driver Amplifier %%%%%%
El_sig = Amplifier("amp_mode","ideal_no_noise","gain_mode","gain","amplification_db",3).process(El_sig);
El_sig = El_sig.normalize("mode","oneone");
%%%%% MODULATE E/O CONVERSION %%%%%%
[Opt_sig] = EML("mode",eml_mode.im_cosinus,"power",3,"fsimu",El_sig.fs,"lambda",laser_wavelength,"bias",vbias,"u_pi",u_pi,"linewidth",laser_linewidth,"randomkey",random_key+1).process(El_sig);
Opt_sig = Fiber("fsimu",Opt_sig.fs,"fiber_length",link_length/1000,"alpha",0.3,"D",0,"lambda0",1310,"gamma",0,"Dslope",0.07).process(Opt_sig);
rop = [-10];
rop = [-8];
bwl = [0.5:0.1:1.5];
fsym = [128:16:170].*1e9;
ber_vnle = [];
ber_mlse = [];
ber_viterbi = [];
@@ -107,71 +56,121 @@ gmi_vnle = [];
gmi_mlse = [];
gmi_mlse_db = [];
for r = 1:length(rop)
for r = 1:length(fsym)
Pform = Pulseformer("fsym",fsym(r),"fdac",4*fsym(r),"pulse","rc","pulselength",16,"alpha",rcalpha);
db_precode = 0;
db_encode = 0;
duob_mode = db_mode.no_db;
apply_pulsef = 1;
[Digi_sig,Symbols,Tx_bits] = PAMsource(...
"fsym",fsym(r),"M",M,"order",18,"useprbs",0,...
"fs_out",fdac,...
"applyclipping",0,"clipfactor",1.5,...
"applypulseform",apply_pulsef,"pulseformer",Pform,...
"randkey",random_key,...
"db_precode",db_precode,"db_encode",db_encode,...
"mrds_code",0,"mrds_blocklength",512,"duobinary_mode",duob_mode).process();
% Digi_sig.spectrum("displayname",'Digi Spectrum','fignum',10,'normalizeTo0dB',0);
%%%%% AWG
% El_sig = M8199A("kover",kover).process(Digi_sig);
El_sig = AWG("fdac",fdac,"f_cutoff",fsym(r),"lpf_active",0,"kover",kover,"bit_resolution",12,"upsampling_method","samplehold","precomp_sinc_rolloff",1).process(Digi_sig);
% El_sig.spectrum("displayname",'Digi Spectrum','fignum',100,'normalizeTo0dB',0);
% El_sig = El_sig.setPower(0,"dBm");
%%%%% Low-pass el. components %%%%%%
% f_nyquist = fsym/2;
% tx_bwl = tx_bw_nyquist.*f_nyquist;
tx_bwl = 50e9;
El_sig = Filter('filtdegree',4,"f_cutoff",tx_bwl,"fs",fdac*kover,"filterType",filtertypes.butterworth,"active",true).process(El_sig);
% El_sig.spectrum("displayname",'Digi Spectrum','fignum',100,'normalizeTo0dB',1);
%%%%% Electrical Driver Amplifier %%%%%%
El_sig = Amplifier("amp_mode","ideal_no_noise","gain_mode","gain","amplification_db",3).process(El_sig);
El_sig = El_sig.normalize("mode","oneone");
%%%%% MODULATE E/O CONVERSION %%%%%%
[Opt_sig] = EML("mode",eml_mode.im_cosinus,"power",3,"fsimu",El_sig.fs,"lambda",laser_wavelength,"bias",vbias,"u_pi",u_pi,"linewidth",laser_linewidth,"randomkey",random_key+1).process(El_sig);
Opt_sig = Fiber("fsimu",Opt_sig.fs,"fiber_length",link_length/1000,"alpha",0.3,"D",0,"lambda0",1310,"gamma",0,"Dslope",0.07).process(Opt_sig);
%%%%%% ROP %%%%%%
Rx_sig = Amplifier("amp_mode","ideal_no_noise","gain_mode","output_power","amplification_db",rop(r)).process(Opt_sig);
Rx_sig = Amplifier("amp_mode","ideal_no_noise","gain_mode","output_power","amplification_db",rop).process(Opt_sig);
%%%%%% PD Square Law %%%%%%
Rx_sig = Photodiode("fsimu",fdac*kover,"dark_current",2e-08,"responsivity",1,"temperature",20,"nep",1.8e-11).process(Rx_sig);
%%%%%% Low-pass RX (PD, El. Connectors and Scope %%%%%%
rx_bwl = rx_bw_nyquist.*f_nyquist;
% rx_bwl = 80e9;
% rx_bwl = rx_bw_nyquist.*f_nyquist;
rx_bwl = 50e9;
Rx_sig = Filter('filtdegree',4,"f_cutoff",rx_bwl,"fs",fdac*kover,"filterType",filtertypes.butterworth,"active",true).process(Rx_sig);
% %%%%%% Low-pass Scope %%%%%%
Lp_scpe = Filter('filtdegree',4,"f_cutoff",110e9,"fs",fadc,"filterType",filtertypes.butterworth,"active",true);
% Rx_sig.spectrum("displayname",'Analog Rx Spectrum','fignum',100,'normalizeTo0dB',1);
%
%%%%%% Scope %%%%%%
Scpe_sig = Scope("fsimu",fdac*kover,"fadc",fadc,...
"delay",0,"fixed_delay",0,"filtertype",filtertypes.butterworth,...
"samplingdelay",0,"rand_samplingdelay",0,"freq_offset",0,"samp_jitter",0,...
"adcresolution",8,"quantbuffer",0.1,'block_dc',1,'lpf_active',1,'H_lpf',Lp_scpe).process(Rx_sig);
"adcresolution",8,"quantbuffer",0.1,'block_dc',1,'lpf_active',0,'H_lpf',Lp_scpe).process(Rx_sig);
Scpe_sig_resampled = Scpe_sig.resample("fs_out",2*fsym);
[~, Scpe_cell, ~, found_sync] = Scpe_sig_resampled.tsynch("reference", Symbols, "fs_ref", fsym, "debug_plots", 1);
Scpe_sig_resampled = Scpe_sig.resample("fs_out",2*fsym(r));
% Scpe_sig_resampled.signal = Scpe_sig_resampled.signal(1:2*length(Symbols));
[~, Scpe_cell, ~, found_sync] = Scpe_sig_resampled.tsynch("reference", Symbols, "fs_ref", fsym(r), "debug_plots", 1);
% Scpe_cell = cell(1);
% Scpe_cell{1} = Scpe_sig_resampled;
Scpe_cell{1}.spectrum("displayname",'Analog Rx Spectrum','fignum',100,'normalizeTo0dB',1);
eq_ = EQ("Ne",[vnle_order1,vnle_order2,vnle_order3],"Nb",[dfe_order],"training_length",len_tr,"training_loops",5,"dd_loops",5,"K",2,"DCmu",mu_dc,"DDmu",[mu_ffe mu_dfe],"DFEmu",0.005,"FFEmu",0,"plotfinal",0,"ideal_dfe",1);
mlse_ = MLSE("DIR",[1,1],"duobinary_output",0,"M",M,"trellis_states",PAMmapper(M,0).levels);
%Duobinary Targeting
if 0
db_ref_sequence = Duobinary().encode(Symbols);
db_ref_constellation = unique(db_ref_sequence.signal);
[eq_signal, eq_noise] = eq_.process(Scpe_cell{1},db_ref_sequence);
mlse_.DIR = [1,1];
[mlse_sig_sd,LLR,gmi_mlse_db(r)] = mlse_.process(eq_signal,Symbols);
mlse_sig_hd = PAMmapper(M,0,"eth_style",0).quantize(mlse_sig_sd);
mlse_sig_hd_precoded = Duobinary().encode(mlse_sig_hd,"M",M);
mlse_sig_hd_precoded = Duobinary().decode(mlse_sig_hd_precoded,"M",M);
tx_symbols_precoded = Duobinary().encode(Symbols);
tx_symbols_precoded = Duobinary().decode(tx_symbols_precoded);
tx_bits_precoded = PAMmapper(M,0,"eth_style",0).demap(tx_symbols_precoded);
rx_bits_mlse = PAMmapper(M,0,"eth_style",0).demap(mlse_sig_hd_precoded);
[~,errors_db_diff_precoded,ber_db_diff_precoded(r),~] = calc_ber(rx_bits_mlse.signal,tx_bits_precoded.signal,"skip_front",100,"skip_end",150,"returnErrorLocation",1);
%B) Just determine BER
rx_bits_mlse = PAMmapper(M,0,"eth_style",0).demap(mlse_sig_hd);
[bits_mlse,errors_mlse,ber_db(r),~] = calc_ber(rx_bits_mlse.signal,Tx_bits.signal,"skip_front",100,"skip_end",150,"returnErrorLocation",1);
%Duobinary Targeting
db_ref_sequence = Duobinary().encode(Symbols);
db_ref_constellation = unique(db_ref_sequence.signal);
[eq_signal, eq_noise] = eq_.process(Scpe_cell{1},db_ref_sequence);
mlse_.DIR = [1,1];
[mlse_sig_sd,LLR,gmi_mlse_db(r)] = mlse_.process(eq_signal,Symbols);
mlse_sig_hd = PAMmapper(M,0,"eth_style",0).quantize(mlse_sig_sd);
mlse_sig_hd_precoded = Duobinary().encode(mlse_sig_hd,"M",M);
mlse_sig_hd_precoded = Duobinary().decode(mlse_sig_hd_precoded,"M",M);
tx_symbols_precoded = Duobinary().encode(Symbols);
tx_symbols_precoded = Duobinary().decode(tx_symbols_precoded);
tx_bits_precoded = PAMmapper(M,0,"eth_style",0).demap(tx_symbols_precoded);
rx_bits_mlse = PAMmapper(M,0,"eth_style",0).demap(mlse_sig_hd_precoded);
[~,errors_db_diff_precoded,ber_db_diff_precoded(r),~] = calc_ber(rx_bits_mlse.signal,tx_bits_precoded.signal,"skip_front",100,"skip_end",150,"returnErrorLocation",1);
%B) Just determine BER
rx_bits_mlse = PAMmapper(M,0,"eth_style",0).demap(mlse_sig_hd);
[bits_mlse,errors_mlse,ber_db(r),~] = calc_ber(rx_bits_mlse.signal,Tx_bits.signal,"skip_front",100,"skip_end",150,"returnErrorLocation",1);
end
% FFE or VNLE
eq_ = EQ("Ne",[vnle_order1,vnle_order2,vnle_order3],"Nb",[dfe_order],"training_length",len_tr,"training_loops",5,"dd_loops",5,"K",2,"DCmu",mu_dc,"DDmu",[mu_ffe mu_dfe],"DFEmu",0.005,"FFEmu",0,"plotfinal",0,"ideal_dfe",1);
[eq_signal_sd, eq_noise] = eq_.process(Scpe_cell{1}, Symbols);
[gmi_vnle(r)] = calc_air(eq_signal_sd, Symbols, "skip_front", 100, "skip_end", 100);
[gmi_gomez(r)] = calc_air(eq_signal_sd, Symbols, "skip_front", 100, "skip_end", 100);
[gmi_vnle(r)] = calc_ngmi(eq_signal_sd,Symbols);
[gmi_bitwise(r)] = calc_gmi_bitwise(eq_signal_sd,Symbols);
snr_vnle(r) = calc_snr(Symbols, eq_signal_sd-Symbols);
eq_signal_sd.plot("displayname",'bla','fignum',118);
% Hard decision on VNLE output
eq_signal_hd = PAMmapper(M, 0).quantize(eq_signal_sd);
@@ -180,19 +179,21 @@ for r = 1:length(rop)
fprintf('BER VNLE: %.2e \n',ber_vnle(r));
fprintf('NGMI VNLE: %.2f \n',gmi_vnle(r)./log2(M));
if 1
% Process through postfilter and MLSE
pf_ncoeffs = 1;
pf_ = Postfilter("ncoeff",pf_ncoeffs,"useBurg",1);
mlse_ = MLSE("duobinary_output",0,'M',M,'trellis_states',PAMmapper(M,0).levels);
[mlse_sig_sd,whitened_noise] = pf_.process(eq_signal_sd, eq_noise);
mlse_.DIR = pf_.coefficients;
alpha(r) = pf_.coefficients(2);
[signalclass_hd,LLR,gmi_mlse(r)] = mlse_.process(mlse_sig_sd,Symbols);
mlse_sig_hd = PAMmapper(M, 0, "eth_style", 0).quantize(signalclass_hd);
rx_bits = PAMmapper(M,0,"eth_style",0).demap(mlse_sig_hd);
[~,~,ber_mlse(r),~] = calc_ber(rx_bits.signal,Tx_bits.signal,"skip_front",100,"skip_end",150,"returnErrorLocation",1);
fprintf('BER: %.2e \n',ber_mlse(r));
fprintf('NGMI MLSE: %.2f \n',gmi_mlse(r)./log2(M));
fprintf('GMI MLSE: %.5f \n',gmi_mlse(r));
% Process through postfilter and MLSE
@@ -205,23 +206,48 @@ for r = 1:length(rop)
mlse_sig_hd = PAMmapper(M, 0, "eth_style", 0).quantize(mlse_sig_sd);
rx_bits = PAMmapper(M,0,"eth_style",0).demap(mlse_sig_hd);
[~,~,ber_viterbi(r),~] = calc_ber(rx_bits.signal,Tx_bits.signal,"skip_front",100,"skip_end",150,"returnErrorLocation",1);
fprintf('FW BER: %.2e \n',ber_viterbi(r));
fprintf('Viterbi BER: %.2e \n',ber_viterbi(r));
end
end
cols = cbrewer2('Paired',8);
d = 1;
figure();hold on
plot(rop,gmi_mlse,'DisplayName','MLSE','Marker','*');
plot(rop,gmi_vnle,'DisplayName','VNLE','Marker','*');
plot(rop,gmi_mlse_db,'DisplayName','MLSE DB Tgt','Marker','*');
figure(11);hold on
plot(fsym.*1e-9,alpha,'DisplayName','VNLE','Marker','x','LineStyle','-','Color',cols(1+d,:));
xlabel('Baudrate in GBd');
ylabel('alpha');
figure(15);hold on
plot(fsym.*1e-9,gmi_gomez,'DisplayName','gomez','Marker','x','LineStyle','-','Color',cols(1+d,:));
plot(fsym.*1e-9,gmi_vnle,'DisplayName','vnle other','Marker','x','LineStyle','-','Color',cols(3+d,:));
plot(fsym.*1e-9,gmi_bitwise,'DisplayName','bitwise','Marker','x','LineStyle','--','Color',cols(5+d,:));
plot(fsym.*1e-9,gmi_mlse,'DisplayName','MLSE','Marker','*');
ylim([0 2.6]);
xlabel('Baudrate in GBd');
ylabel('GMI');
figure();hold on
plot(rop,ber_vnle,'DisplayName','VNLE');
plot(rop,ber_mlse,'DisplayName','MLSE','Marker','*');
plot(rop,ber_viterbi,'DisplayName','Viterbi','Marker','*');
plot(rop,ber_db_diff_precoded,'DisplayName','MLSE db diff','Marker','*');
plot(rop,ber_db,'DisplayName','MLSE db','Marker','*');
figure(13);hold on
plot(fsym.*1e-9,ber_vnle,'DisplayName','VNLE','Marker','x','LineStyle','-','Color',cols(1+d,:));
plot(fsym.*1e-9,ber_mlse,'DisplayName','MLSE','Marker','x','LineStyle','-','Color',cols(3+d,:));
plot(fsym.*1e-9,ber_viterbi,'DisplayName','Viterbi','Marker','x','LineStyle','--','Color',cols(5+d,:));
% plot(bwl,ber_db_diff_precoded,'DisplayName','MLSE db diff','Marker','.','MarkerSize',15,'LineStyle','-');
% plot(bwl,ber_db,'DisplayName','MLSE db','Marker','.','MarkerSize',15,'LineStyle','-');
xlabel('Baudrate in GBd');
ylabel('BER');
set(gca, 'yscale', 'log');
% ylim([1e-6 0.1]);
legend
% Auxiliary nested helper for numerically stable log-sum-exp
function s = logsumexp(a)
% LOGSUMEXP Compute log(sum(exp(a))) in a numerically stable way
m = max(a);
s = m + log(sum(exp(a - m)));
end